The present invention relates to a locking mechanism for systems employing rotatable indicia carrying members. It has particular application in systems in which rotatable indicia carrying members are used for printing purposes, such as data recorders and particularly credit card bill printing devices. It is important in such devices that the rotatable indicia carrying members be positioned so that the desired indicia is accurately aligned with the appropriate spaces on a bill manifold. Also, during the actual printing operation, which usually involves a reciprocating platen which applies pressure to both the bill manifold and the indicia carrying member, it is important that the rotatable indicia carrying member be rigidly locked against movement, so that it does not blur the printed image.
In providing a mechanism for aligning and locking rotatable indicia carrying members, known prior art devices have utilized relatively complex mechanical linkages having numerous parts. The linkages have been designed so that the aligning and the locking functions are each effected through individual movements of their respective members, which movements are then coordinated by appropriate linkages. With linkages involving many relatively moving parts, it becomes often necessary to check the alignment of the parts themselves so that their own registration, and their respective coordination, will be proper.